1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
|
//=======- CaptureTrackingTest.cpp - Unit test for the Capture Tracking ---===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/CaptureTracking.h"
#include "llvm/AsmParser/Parser.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/SourceMgr.h"
#include "gtest/gtest.h"
using namespace llvm;
TEST(CaptureTracking, MaxUsesToExplore) {
StringRef Assembly = R"(
; Function Attrs: nounwind ssp uwtable
declare void @doesnt_capture(i8* nocapture, i8* nocapture, i8* nocapture,
i8* nocapture, i8* nocapture)
; %arg has 5 uses
define void @test_few_uses(i8* %arg) {
call void @doesnt_capture(i8* %arg, i8* %arg, i8* %arg, i8* %arg, i8* %arg)
ret void
}
; %arg has 50 uses
define void @test_many_uses(i8* %arg) {
call void @doesnt_capture(i8* %arg, i8* %arg, i8* %arg, i8* %arg, i8* %arg)
call void @doesnt_capture(i8* %arg, i8* %arg, i8* %arg, i8* %arg, i8* %arg)
call void @doesnt_capture(i8* %arg, i8* %arg, i8* %arg, i8* %arg, i8* %arg)
call void @doesnt_capture(i8* %arg, i8* %arg, i8* %arg, i8* %arg, i8* %arg)
call void @doesnt_capture(i8* %arg, i8* %arg, i8* %arg, i8* %arg, i8* %arg)
call void @doesnt_capture(i8* %arg, i8* %arg, i8* %arg, i8* %arg, i8* %arg)
call void @doesnt_capture(i8* %arg, i8* %arg, i8* %arg, i8* %arg, i8* %arg)
call void @doesnt_capture(i8* %arg, i8* %arg, i8* %arg, i8* %arg, i8* %arg)
call void @doesnt_capture(i8* %arg, i8* %arg, i8* %arg, i8* %arg, i8* %arg)
call void @doesnt_capture(i8* %arg, i8* %arg, i8* %arg, i8* %arg, i8* %arg)
ret void
}
)";
LLVMContext Context;
SMDiagnostic Error;
auto M = parseAssemblyString(Assembly, Error, Context);
ASSERT_TRUE(M) << "Bad assembly?";
auto Test = [&M](const char *FName, unsigned FalseMaxUsesLimit,
unsigned TrueMaxUsesLimit) {
Function *F = M->getFunction(FName);
ASSERT_NE(F, nullptr);
Value *Arg = &*F->arg_begin();
ASSERT_NE(Arg, nullptr);
ASSERT_FALSE(PointerMayBeCaptured(Arg, true, true, FalseMaxUsesLimit));
ASSERT_TRUE(PointerMayBeCaptured(Arg, true, true, TrueMaxUsesLimit));
BasicBlock *EntryBB = &F->getEntryBlock();
DominatorTree DT(*F);
Instruction *Ret = EntryBB->getTerminator();
ASSERT_TRUE(isa<ReturnInst>(Ret));
ASSERT_FALSE(PointerMayBeCapturedBefore(Arg, true, true, Ret, &DT, false,
FalseMaxUsesLimit));
ASSERT_TRUE(PointerMayBeCapturedBefore(Arg, true, true, Ret, &DT, false,
TrueMaxUsesLimit));
};
Test("test_few_uses", 6, 4);
Test("test_many_uses", 50, 30);
}
struct CollectingCaptureTracker : public CaptureTracker {
SmallVector<const Use *, 4> Captures;
void tooManyUses() override { }
bool captured(const Use *U) override {
Captures.push_back(U);
return false;
}
};
TEST(CaptureTracking, MultipleUsesInSameInstruction) {
StringRef Assembly = R"(
declare void @call(i8*, i8*, i8*)
define void @test(i8* %arg, i8** %ptr) {
call void @call(i8* %arg, i8* nocapture %arg, i8* %arg) [ "bundle"(i8* %arg) ]
cmpxchg i8** %ptr, i8* %arg, i8* %arg acq_rel monotonic
icmp eq i8* %arg, %arg
ret void
}
)";
LLVMContext Context;
SMDiagnostic Error;
auto M = parseAssemblyString(Assembly, Error, Context);
ASSERT_TRUE(M) << "Bad assembly?";
Function *F = M->getFunction("test");
Value *Arg = &*F->arg_begin();
BasicBlock *BB = &F->getEntryBlock();
Instruction *Call = &*BB->begin();
Instruction *CmpXChg = Call->getNextNode();
Instruction *ICmp = CmpXChg->getNextNode();
CollectingCaptureTracker CT;
PointerMayBeCaptured(Arg, &CT);
EXPECT_EQ(7u, CT.Captures.size());
// Call arg 1
EXPECT_EQ(Call, CT.Captures[0]->getUser());
EXPECT_EQ(0u, CT.Captures[0]->getOperandNo());
// Call arg 3
EXPECT_EQ(Call, CT.Captures[1]->getUser());
EXPECT_EQ(2u, CT.Captures[1]->getOperandNo());
// Operand bundle arg
EXPECT_EQ(Call, CT.Captures[2]->getUser());
EXPECT_EQ(3u, CT.Captures[2]->getOperandNo());
// Cmpxchg compare operand
EXPECT_EQ(CmpXChg, CT.Captures[3]->getUser());
EXPECT_EQ(1u, CT.Captures[3]->getOperandNo());
// Cmpxchg new value operand
EXPECT_EQ(CmpXChg, CT.Captures[4]->getUser());
EXPECT_EQ(2u, CT.Captures[4]->getOperandNo());
// ICmp first operand
EXPECT_EQ(ICmp, CT.Captures[5]->getUser());
EXPECT_EQ(0u, CT.Captures[5]->getOperandNo());
// ICmp second operand
EXPECT_EQ(ICmp, CT.Captures[6]->getUser());
EXPECT_EQ(1u, CT.Captures[6]->getOperandNo());
}
|
